Decreased bone resorption with soy isoflavone supplementation in postmenopausal women

Harkness et al., 2004 | J Womens Health (Larchmt) | Rct

Citation

Harkness Laura S, Fiedler Karen, ... Lerner Edith. Decreased bone resorption with soy isoflavone supplementation in postmenopausal women. J Womens Health (Larchmt). 2004-Nov;13(9):1000-7

Abstract

OBJECTIVE: To investigate the effect of soy isoflavone supplementation on bone mineral density (BMD) and markers of bone turnover in postmenopausal women. METHODS: In this randomized, placebo-controlled clinical trial, we used a crossover design to test the effect of soy isoflavone (110 mg/day) (1.3:1.0:0.22 ratio of genistein/daidzein/ glycitein) on bone formation, bone resorption, bone mineral content (BMC), and BMD for 6 months. RESULTS: Postmenopausal women (n = 19), mean age 70.6 +/- 6.3 years and mean time since menopause 19.1 +/- 5.5 years, were given isoflavone supplements for 6 months. There was a 37% decrease in urinary concentrations of type 1 collagen alpha1-chain helical peptide (HP), a marker of bone resorption, during the isoflavone supplementation compared with baseline (p < 0.05) and a significant difference in mean (SE) HP excretion levels when isoflavone was compared with placebo (43.4 +/- 5.2 vs. 56.3 +/- 7.2 microg/mmol creatinine [cr], p < 0.05). With isoflavone supplementation, mean spine BMD at L2 and L3 was significantly greater when treatment was compared with control, with a difference between means of 0.03 +/- 0.04 g and 0.03 +/- 0.04 g (p < 0.05), respectively. There were nonsignificant increases from baseline for total spine BMC (3.5%), total spine BMD (1%), total hip BMC (3.6%), and total hip BMD (1.3%) with the isoflavone treatment. CONCLUSIONS: Soy isoflavone, in isolated form, was effective in this study to significantly decrease bone resorption in postmenopausal women. Further investigation needs to be done to evaluate the long-term effects of soy isoflavone on bone mass and fracture risk.

Key Findings

Postmenopausal women (n = 19), mean age 70.6 +/- 6.3 years and mean time since menopause 19.1 +/- 5.5 years, were given isoflavone supplements for 6 months. There was a 37% decrease in urinary concentrations of type 1 collagen alpha1-chain helical peptide (HP), a marker of bone resorption, during the isoflavone supplementation compared with baseline (p < 0.05) and a significant difference in mean (SE) HP excretion levels when isoflavone was compared with placebo (43.4 +/- 5.2 vs. 56.3 +/- 7.2 mi

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population postmenopausal women
Sample Size 19
Age Range mean age 70.6
Condition See abstract

MeSH Terms

  • Aged
  • Aged, 80 and over
  • Biomarkers
  • Bone Density
  • Bone Resorption
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Isoflavones
  • Middle Aged
  • Osteoporosis, Postmenopausal
  • Postmenopause
  • Risk Factors
  • Soybean Proteins
  • Time Factors
  • Treatment Outcome

Evidence Classification

  • Level: Rct
  • Publication Types: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, P.H.S.
  • Vertical: soy

Provenance

  • PMID: 15665657
  • DOI: (not available)
  • PMCID: Not in PMC
  • Verified: 2026-04-09 via PubMed E-utilities API

Source extracted via PubMed E-utilities API on 2026-04-09